The present invention relates to a shifting mechanism for an automotive transmission, and particularly to an externally mounted standard pattern shifter with a reverse lockout.
Some transmissions have shift control shafts extending from a side of the gear housing and radially extending arms fixed to the shafts. The arms are pivotally connected to coupling rods extending toward a shifting mechanism mounted remotely on the transmission. The coupling rods at this end are pivotally connected to fingers extending downward from a shifter of the type to be discussed.
External mount gear shifters are well known; U.S. Pat. Nos. 3,052,135, 3,172,301 and 3,323,387 to G. H. Hurst, Jr. et al are representative of such shifters for conventional shift patterns. Known external mount shifters generally employ fingers pivoted within a housing and a shift lever likewise pivoted in the housing. The lever may have a lower extension which directly engages a finger when moved laterally, or may act on fingers indirectly through various arrangements of pins and springs. One of the most popular external mount shifters is the Hurst shifter having a mechanism of the type shown in U.S. Pat. No. 3,323,387. It employs a selector pin carried on the lower end of a shift lever pivotable about two axes. The fingers are side by side in the housing and have holes which are aligned when the transmission is in neutral. The selector pin has an engaging head within the holes and acts upon the fingers with which it is aligned by appropriate lateral movement of the shifter. In practice, the fingers are not flush in the housing and tend to separate further after prolonged use. At the same time, the engaging head on the pin eventually wears until it can slip between the fingers.
U.S. Pat. No. 3,323,387 discloses a four speed shifter with reverse offset and parallel to one arm of the H. Reverse is engaged by bearing on the shifter so that it urges the selector pin to a lower level before the hole in the finger controlling reverse can be engaged. There is no five speed embodiment disclosed, and likewise there is no means suggested for locking out reverse in a five speed transmission.